As a device for scanning a light beam, a light scanning device using a polygon mirror or a galvano mirror is widely spread. A small-sized light scanning device using a MEMS mirror device manufactured by means of MEMS (Micro Electro Mechanical Systems) technology has been also proposed. The MEMS mirror device is a device that moves a scan mirror, which includes components such as an elastic beam which are integrally molded with silicon or the like, in a reciprocating motion by electromagnetic force, electrostatic force, or the like, and is a minute electronic mechanical component that is capable of scanning a light beam.
There is a proposition of an image projection apparatus that forms one image by displaying two display images on a screen with light beams, by using a MEMS mirror device (e.g., refer to patent reference 1). This apparatus joins two display images displayed as a result of an individual scan with two light beams emitted from two light sources so that they are slightly overlapped with each other, thereby displaying one large-area image.